Reducing Cost and Solving Problems in BRIDGES AND HIGHWAYS

Transcription

1 Reducing Cost and Solving Problems in BRIDGES AND HIGHWAYS DEC 15 Building tomorrow s bridges and highways today.

2 Service Life and Lower Life Cycle Costs With ChrōmX Concrete Reinforcing Steels ChrōmX concrete reinforcing steels provide high strength with varying levels of corrosion resistance, so designers can utilize the high strength efficiencies and best match the corrosion protection requirements of the structure. The service life (the time to first repair) is driven by the corrosion of the reinforcing steel. Reinforcing steel corrosion begins when the chloride concentration at the steel surface reaches the critical chloride threshold (CT) value of that steel. The corrosion continues at the corrosion rate (CR) of the steel, eventually causing cracking and spalling of the concrete and deterioration of the structure. Damage (Cost) Stage 1 ChrōmX 9100 Stage 2 ChrōmX 9100 Stage 1 Stage 2 Stage 3 Economic Limit Barrier System Life Corrosion Initiation Time (years) Initiation Propagation Repair Potential End of Operational Service Life Repair Event Reduces Damage End of Economic Service Life Corrosion Initiation > 100 Black Steel ChrōmX 9100 Chloride Threshold (lb/y 3 ) Black Bar Corrosion Protection Epoxy Coated Rebar (ECR) 2.57 Galvanized 3.17 ChromX 4000 Series 6.34 ChromX 9000 Series The CT of ChrōmX 9100 is 4X that of Black Bar and twice that of ChrōmX In addition, both ChrōmX 9100 and 4100 have a CR value of 1/3 that of Black Bar. These higher CT and lower CR values are the reason the ChrōmX products extend the structure s service life, saving repair and maintenance costs, resulting in lower life cycle costs compared to other steel reinforcing products. Chart Notes: 1 Darwin, David et al, Critical Chloride Corrosion Threshold for Galvanized Reinforcing Bar, The University of Kansas Center for Research, Inc. (Dec 2007). 2 ECR Chloride Threshold set at black bar s CT. Perfectly applied epoxy-coating performs well in laboratory tests, but field studies prove that the coating does not survive field handling and installation, and therefore provides little to no protection. 3 ChrōmX 4100 comparison figure based on Tourney Consulting Group, LLC, Reinforcing Steel Comparative Durability Case Studies and 100 Year Service Life Cost Analysis Report, Tourney Consulting Group, LLC Comparative Table of Service Life and Life Cycle Cost Analysis (LCCA) in Bridge Decks Reinforcing Bar Service Life* Est. Initial Cost 50-Year LCCA** 75-Year LCCA** 100-Year LCCA** Black Bar 25 $7.92 $21.22 $27.39 $30.25 Epoxy Coated 34 $10.62 $21.18 $26.08 $27.44 Galvanized 50 $12.70 $16.87 $19.71 $22.97 ChrōmX $11.16 $11.16 $16.45 $17.91 ChrōmX 4100 w/ CNI*** >100 $13.36 $13.36 $13.36 $13.36 ChrōmX 9100 >100 $15.06 $15.06 $15.06 $15.06 Stainless (UNS S32304) >100 $25.56 $25.56 $25.56 $25.56 * Service lives estimated based on CT values determined in Critical Chloride Corrosion Threshold for Galvanized Reinforcing Bars, David Darwin, et al, Univ. of Kansas Center for Research, Inc. (Dec. 2007), as well as CT and CR values, and Stadium Modeling for a concrete bridge deck with 1.5 in. (37.5 mm) Bridge Mix LP concrete cover according to Reinforcing Steel Comparative Durability Case Studies and 100 Year Service Life Cost Analysis Report, Tourney Consulting Group, LLC (2015). ** Estimated net present value (NPV) per square foot of the total life cycle costs of the bridge deck. *** Adding 2 gallons of calcium nitrite as a concrete additive at an estimated cost of $2.20 per square foot has been shown to further enhance ChrōmX 4100 s corrosion performance.

3 Service Life Designs With the full ChrōmX product line ChrōmX 9100 Formerly MMFX 2 Areas of the same bridge have different corrosion protection requirements. The full ChrōmX product line (9100, 4100 and 2100) allows all designers to select the product that best fits the application. Bridge Corrosion Exposure Zones Atmospheric De-icing salt & spray Splash Submerged Embedded Atmospheric Zone. The atmosphere to which the bridge is exposed varies widely with the location of the bridge. Inland bridge atmosphere is relatively benign and therefore raises low to no corrosion concern, while bridges over or near seawater have higher corrosion potential. Atmospheric bridge members for inland bridges can use ChrōmX 2100, while bridges exposed to seawater should consider using ChrōmX 4100 or Deck and Deicing Salt Spray Zone. ChrōmX 9100 should be used in these areas of a bridge where deicing salts are used. Splash Zone. The splash zone is a severe corrosive environment requiring ChrōmX 9100 s corrosion protection. Submerged Zone. While actually less corrosive than the splash zone, designers should consider ChrōmX 9100 or 4100 for the submerged zone. Embedded Zone. There is usually low corrosion potential in the embedded zone depending on the composition and contents of the soil, therefore ChrōmX 2100 may be a good choice. Significant savings are actually realized upon first repair and accumulate throughout the service life. Savings Realized Upon First Repair Costs for Reinforcement & Repair ($/sq ft) $60 $50 $40 $30 $20 $10 $ 0 ChrōmX 9100 vs ECR (Deicing) Cumulative Costs After Initial Repair - Year 34 In-Place Costs ChrōmX 9100 Repair Costs In-Place Costs ECR Huguenot Bridge, Richmond VA Photo by Trevor Wrayton from VDOT On average, rebar accounts for only 1% - 4% of the total cost of construction, yet this relatively small cost item ultimately determines the operational service life of the multi-million dollar structure. In addition, repair costs easily overshadow minor differences in initial construction costs, so using ChrōmX rebar can greatly reduce the overall cost of a structure.

4 High Strength Bridge Designs With ChrōmX Concrete Reinforcing Steels Use the high strength Grade 100 properties of all three ChrōmX steels to efficiently design and construct better bridges, reducing upfront construction costs. High Strength Tensile Properties ChrōmX Specification ASTM A1035 CL ASTM A1035 CM ASTM A1035 CS Grade 100 [690] 100 [690] 100 [690] Tensile Strength, min, psi 130, , ,000 [MPa] [900] [1030] [1030] Yield Strength (0.2% offset) 100, , ,000 min, psi [MPa] [690] [690] [690] Elongation in 8 in. [200 mm], min Bar Designation No. 3 through 11 [10 through 36] , 18 [43,57] Stress KSI Stress vs. Strain Curves for ASTM A1035, CS, CM & CL ASTM A1035 CS ChrōmX 9100 ASTM A1035 CM ChrōmX 4100 ASTM A1035 CL ChrōmX Strain ACI ITG-6R-10 Design Guide for the Use of ASTM A1035/A1035M Grade 100 (690 MPa) Steel Bars for Structural Concrete ICC-ES AC429 & ESR 2107 Acceptance Criteria for High-Strength Steel Reinforcing Bars AASHTO LRFD Bridge Specification Bridge Design for the Use of ASTM A1035/A1035M Grade 100 (690 MPa) Steel Bars for Bridge Structures

5 AASHTO LRFD Bridge Design Specifications allow for the design of bridges up to 100 ksi yield Maximum Tensile Strengths (KSI) of Reinforcement for Use in Bridge Designs 1 Seismic Foundations Columns / Walls Decks Breams / Girders Zones Abutments Piles Pile Caps Vertical Confinement Top & Bottom Tension Compression Shear Zone (2) Zone (3) 100 (3) 100 (3) 100 (4) 100 (3) (2) Zone (3) 100 (3) 100 (3) N (5) 100 (3) (2) Zone (3) 100 (3) 100 (3) N (5) 100 (3) (2) (1) Design Guide for Use of ASTM A1035 High-Strength Reinforcement in Concrete Bridge Elements with Consideration of Seismic Performance, H.G. Russell, S.K. Ghosh, Mehdi Saiidi (2011) and Design Guide for Use of ASTM A1035 High-Strength Reinforcement in Concrete Bridge Elements in AASHTO Seismic Zone 2, S.K. Ghosh (2012). (2) Yield strength limited to 60 ksi for shear-friction calculation. (3) Yield strength of transverse reinforcement limited to 60 ksi for shear strength computations. (4) Required shear strength must be calculated per Articles and and minimum shear reinforcement must be provided per Article of the AASHTO Guide Specifications for LRFD Bridge Design. (5) Not recommended. Concrete reinforcing steel used must meet ASTM A706 seismic requirements. Examples of Efficient Bridge Design Techniques Structural Design Guidelines for Concrete Bridge Decks Using Corrosion Resistant Reinforcing (CRR) Bars by Virginia Center for Transportation Innovation & Research Reducing steel weight by 36% Thinning clear cover from 2.5 to 2.0 inches Identifying significant savings in construction costs and time Improving serviceability Reference: Final Report VCTIR 15-R10 (October 2014) Alternative to Post-Tensioning for Pier Cap by econstruct.usa, LLC Without ChrōmX With ChrōmX Simplifying construction steps Reducing pier cap weight Reducing concrete Saving on reinforcement costs Reference: MMFX Steel Alternative to Post-Tensioning for Pier Cap, econstruct.usa, LLC (2015) Specifications and Codes ASTM A1035 CS, CM, CL Grades 100 and 120 AASHTO MP18 AASHTO LRFD Bridge Design Specification ACI 318 ACI ITG-6R-10 Design Guide ICC-ES Evaluation Report ESR-2107 ICC-ES Acceptance Criteria AC429 USAGE Unified Facilities Guide Specification States and Provinces Tested and Accepted Alabama Alberta Arizona Colorado Connecticut Delaware Florida Georgia Idaho Indiana Iowa Kentucky Massachusetts Maine Manitoba Michigan New Hampshire New Mexico North Carolina Ohio Oklahoma Pennsylvania South Carolina Texas Virginia Washington Utah

6 Bridge Applications MMFX Steel Installations in North America British Columbia Alberta Manitoba Quebec New Brunswick Saskatchewan Ontario Nova Scotia Alaska Washington Vermont Maine Oregon Idaho Montana Wyoming North Dakota South Dakota Minnesota Iowa Wisconsin Michigan New York Pennsylvania New Hampshire Massachusetts Rhode Island Connecticut New Jersey Nevada Utah Colorado Nebraska Missouri Illinois Indiana Ohio West Virginia Virginia Delaware Maryland Washington DC California Arizona New Mexico Kansas Oklahoma Arkansas Kentucky Tennessee North Carolina South Carolina Alabama Mississippi Georgia Texas Hawaii Louisiana Florida Legend Puerto Rico Canada Bridges with ChrōmX U.S. Bridges with ChrōmX Dowel Bar Applications Uncoated Corrosion Resistant Steel Pavement Dowel and Tie Bars ChrōmX brand dowel bars and tie bars are available. Smooth round pavement dowels serve as load transfer devices (LTD s) at transverse joints in plain jointed concrete pavement (PJCP). Dowel bars are generally 18 long by 1 ¼ or 1 ½ in diameter, spaced 12 across the transverse joints, depending on pavement thickness and traffic considerations. The placement of dowel bars is made by either using: dowel bar baskets prior to pouring concrete or dowel bar inserter equipment as part of a retrofit or repair project.

7 Technology The MMFX Story MMFX Technologies Corporation is a global specialty steel company dedicated to applying innovative steel technologies to multiple product lines. With its steel production partners, OEM manufacturers and industry leaders, MMFX delivers solutions to problems faced by steel consumers. As a dependable technical resource, MMFX continuously strives to deliver unmatched value to its customers through the application of advanced nano steel technology. The MMFX Technology Difference Over 100,000 tons of steel placed in concrete MMFX has removed long-standing limitations faced by structural engineers and the construction industry by introducing its ChrōmX brand high strength concrete reinforcing steel products with varying levels of corrosion resistance, so designers can utilize the high strength efficiencies and best match the corrosion protection requirements of a given project. ChrōmX 9000 (formerly MMFX 2 ) concrete reinforcing steels can be specified as ASTM A1035 CS either Grade 100 or 120. This chromium steel provides high corrosion protection for severe corrosive environments caused by seawater, aggressive soils and deicing salts. Designers can meet 100-year service life requirements called for on many infrastructure projects by specifying ChrōmX ChrōmX 4000 (ASTM A1035 CM Grade 100 or 120) offers the same high strength benefits with a medium level of corrosion resistance for projects requiring 40 to 60 years of service life, depending on the specific application and design. MMFX steel is specially formulated out of low carbon, chromium alloy steel that lacks the typical grain boundaries of carbides and ferrites found in conventional carbon steel. Steel made using MMFX nanotechnology significantly minimizes the formation of corrosive currents that are inherent in carbon steel bars, thus reducing the driving force behind corrosion. The resulting steel bar is strong yet ductile and provides up to five times more corrosion resistance than conventional carbon steel without the use of coatings. ChrōmX 2000 (ASTM A1035 CL Grade 100 or 120) is a low cost product ideal for construction projects in which high strength designs reduce the amount of steel used, improving constructability, and reducing construction time and costs for the owner. By specifying ASTM A1035 CS, CM or CL, designers can take advantage of the high strength efficiencies and match the appropriate corrosion resistance for the targeted service life of the structure Eligible for LEED credits in Materials and Resources Innovation in Design In conjunction with its industry partners and OEM manufacturers, MMFX continues to develop and deliver additional steel products utilizing the MMFX nanotechnology to the market, such as thread bar, anchor bolts, and couplers. MMFX products are marketed and sold globally through MMFX s operating subsidiaries (MMFX Steel Corporation of America and MMFX Steel DMCC), as well as OEM manufacturers and regional licensees. (866) TODAY S STEEL STANDARD FINAL_ f

8 How to Order For specific product related questions about ChrōmX or to place an order, we invite you to contact us at (866) or one of our partners listed below. STOCKING DISTRIBUTORS Cascade Steel Rolling Mills (Licensee) (503) , (800) , Construction Materials Group dba Rockingham Steel/Transcon Supply (540) , Metal Partners (973) , Steelcon Supply (304) , West Virginia (407) , Florida Stuart Building Products (954) , Florida Williams Form Engineering (503) , QUALIFIED DISTRIBUTORS Adelphia Metals, LLC (952) , New Jersey Harris Supply Solutions, Inc. (443) , Maryland FOR THREADED BAR, SOIL NAILS & FASTENERS Williams Form Engineering, FOR COUPLERS Barsplice Products, Inc. Dextra Erico HRC Williams Form Engineering For more technical information, please visit our website Campus Drive, Suite 100, Irvine, CA Phone: (949) Toll Free: (866) MMFX Technologies Corporation. All Rights Reserved.